In the morning, we met with Dr. Bo Göran from KTH Stockholm who led us on an architectural bus tour of Stockholm and outlying areas. He gave a brief history of State and institutional buildings in the central city area and spoke to us about the historical building methods, primarily masonry in response to the city’s history of fire.
Just south of Stockholm, we observed several different multi-unit residential housing projects under construction as well as prototypical conditions for single-family suburban dwellings. One of the salient features of Swedish suburban developments was the preservation of greenspace and provision for community services, such as preschools and parkspace.
Dr. Göran informed us of the energy strategy of Sweden, where approximately 50% of electricity is produced by hydroelectric and the other 50% by nuclear. To offset the need for fuel oil, natural gas, or electric heating, many communities have developed a district heating infrastructure, which provides for up to 5,000 homes. This is further assisted by geothermal loops, which can be drilled as deep as 200 meters through rock.
According to Dr. Göran, most modern dwellings have been constructed from high-quality precast concrete systems, some of which utilize an aerated autoclaved production technique, but wood framing systems have seen increasing popularity over the last decade. These systems can either be a precut wood stud wall systems or “massive timber” cross-laminated timber panels.
One project that we visited that does not fit into either of these categories was the IKEA / Skanska BO KLOK system, which is comprised of volumetric modules constructed from wood stud walls. These modules are shipped with all finishes already installed and an entire building consisting of six dwelling units and twelve modules can be finished in one week after all site work is completed. The system is placed upon a prefabricated concrete slab on grade and the modules are installed on a highly precise construction schedule. The project can only be placed in locations that meet particular criteria, including a flat site to reduce site grading costs, proximity to public transit, and creating a mixed income community.
The BO KLOK program has been wildly popular in Sweden, with thousands of families applying for the 3,000 units produced so far, with Skanska limiting production to 800 units per year to keep both quality and demand at a high level. The program has been highly successful from a public relations standpoint for Skanska, where 98% of BO KLOK buyers who have been polled would recommend the homes to friends and colleagues. BO KLOK is designed to be affordable enough so a single nurse with one child, the average Swedish family, can afford to purchase a home that would otherwise be forced to rent an apartment. The units cost approximately 20% less than similar units since the designers focused on optimizing functionality on a smaller footprint and not allowing any customization.